Convert 1929 from Negative Ground back to Positive

[Canton_Model_A's]

Here is an interesting question. the Previous owner who did the 12v conversion on my 1929 put it to Negative Ground. My question is, how hard is it to put it back to Positive ground?

I took a look at my 'A' yesterday to confirm. Should I just leave it like this or attempt the conversion back to Positive ground from Negative.

Thanks!